The terms thin-film battery or microbattery are conventionally used to designate an assembly comprising a support substrate and, on a surface of the substrate, a stack of layers forming an active battery element, the stack particularly comprising a solid electrolyte layer between a negative electrode and a positive electrode. The total thickness of a thin-film battery is typically in the range from a few tens to a few hundreds of μm, for a surface area in the range from a few mm2 to a few cm2, which enables to house the battery in very small spaces and further enables to manufacture batteries of variable flexibility (according to the characteristics of the support substrate). To form such batteries, it is known to use techniques of sputtering through a shadow mask. Such techniques comprise placing a shadow mask above the support substrate and sputtering, through the mask, the different layers forming the active battery element. In such batteries, the positive and negative contact terminals of the battery, intended to be connected to an external device, are generally arranged on the same side of the support substrate, and have their surfaces of connection to the outside oriented in the same direction.